[moron4hire]

This is what I was trying to get at. A lot of the data I deal with is directed, cyclic graphs. Actually, I personally think most data sets we care about are actually directed graphs of some kind, but we've gotten so used to thinking of them as trees that we force the metaphor too far. I mean, file systems are an excellent example of a thing we actually want to be a graph but we've forced into being a tree. Because otherwise why would we have ever invented symlinks?

[GrowingSideways]

There's a bunch of literature about accessing graphs through tree lenses. I'm not sure exactly what you're looking for.

SQL certainly forces you to look at graphs as trees. Do you have an specific interface you're trying to access? If you're trying to use a graph database, why mention APIs and SQL?